OBJECTIVETo retrospectively evaluate the clinical evaluation of preoperative lumbar T2 sagittal MRI image in predicting the recurrent lumbar disc herniation (RLDH).

METHODSBetween January 2009 and April 2011, 28 patients were diagnosed as recurrent L4-5 disc herniation within 2.5 years after surgery, and 25 of them were included in the study as relapse group. At the same time, selected 25 patients implemented the same surgical methods in the same level as a control group randomly, they were all with good to excellent result and the follow-up time was at least 2.5 years. There was no statistical significance between the two groups in gender, age and body mass index(BMI) (P > 0.05). The lumbar MRI image of two groups of patients before surgery were collected and analyzed, with the disc degeneration grade classified. The χ(2) test was used to analyzed the difference of degeneration between the two groups of patients before surgery. Rank correlation analysis evaluated the correlation between disc degeneration and the period of time from the first operation to the recurrence.

RESULTSIn terms of preoperative lumbar disc degeneration, there were 22 cases of low-grade disc degeneration and 3 cases of advanced disc degeneration in the relapse group and 5 cases and 20 cases respectively in the control group. there was significant difference between two groups (χ(2) = 23.27, P < 0.05), low-grade disc degeneration (gradesIand III) was significantly more frequent in the relapse group than in the control group. The patients with low-grade disc degeneration had a higher risk of recurrence, that was the risk of recurrent disc herniation increased by a factor of 4.4 from advanced disc degeneration to low-grade disc degeneration(OR = 4.4, 95%CI:1.983-9.765, P < 0.05). In cases of recurrence, the time interval between primary surgery and the recurrence of the patient with advanced disc degeneration was longer compared with low-grade disc degeneration (r = 0.733, P < 0.05).

CONCLUSIONSPreoperative lumbar MRI image may suggest the possibility of the recurrence lumbar disc herniation.Light disc degeneration is an important risk factor for recurrent disc herniation, and the time interval between primary surgery and the recurrence is positively correlated with severity of disc degeneration.